Questions tagged [circuit-analysis]

Circuit (Network) analysis is the process of finding the voltages across, and the currents through, every component in the network.

439 questions
3k views

Stability factors of a voltage divider bias circuit

I am trying to derive the stability factors of a voltage divider bias circuit. I could derive S,S', however, I'm facing some problem with the derivation of S''. Please help me in this regard. How to ...
79 views

Subthreshold Analog Accelerator - How is current derived through two sub-threshold transistors in series?

Was browsing the following paper: Fick, Laura, et al. "Analog in-memory subthreshold deep neural network accelerator." 2017 IEEE Custom Integrated Circuits Conference (CICC). IEEE, 2017. When I ran ...
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Appoximation of a transient response of a more complex circuit

I have a "complicated" circuit that I want to approximate as a simple harmonic oscillator. More info below. I have a parallel LRC circuit, with some extra input and output load resistors and coupling ...
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Idealized and simplified source with constant power supply

I have a multiport network in which I want to send an AC signal of constant average power, independent of the network's input impedance on the source side. While we would need matching networks and ...
63 views

Voltage increase by connecting Voltmeter

I've got this scheme. V1 and V2 are voltmeters without their own power supply. (V1 gets power from the measured circuit, V2 is powered separately, but in this case from the same power supply.) The ...
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Q: Finding the current through the capacitor

Having a hard time trying to find the current through the capacitor I don't know what method to use. simulate this circuit – Schematic created using CircuitLab This is how far I have gotten: ...
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Nodal Analysis - solving 2 variables with 3 equations

There are three conditions: before the switch is closed (opened) while the switch is closed (closed) after the switch is closed (opened) I think I need to solve them sequentially, because the system ...
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Diode circuit analysis with two diodes in series

simulate this circuit – Schematic created using CircuitLab In the above schematic the CVD model is being used, with a voltage drop of 0.6 V, for all three diodes. The input voltage sweeps from -...
229 views

Linear vs. Audio Taper for RC Network

I'm building a distortion pedal and I was wondering which tapers to use for which potentiometers in the tone control section. I normally design my own circuits, but I'm going by someone else's ...
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What are limitations of Millers theorem for amplifier?

I mean to say that are the two circuits one original and other its miller/ drawn exactly equal in all respects or their are some difference in some respect if so please mention. I am not able to ...
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What am I doing wrong with this Wheatstone Bridge?

Experienced experimentalists, be aware that this is probably going to sound like a stupid question: I am having a LOT of trouble predicting the output of this Wheatstone bridge circuit. I am trying ...
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MOSFET current mirror with compensation

I am trying to understand the difference between a MOSFET current mirror with and without compensation (Replace Q3 with a short circuit). In the case of a current mirror without compensation, V1 ...
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In a forward bias diode, why do electrons continue into neighboring holes?

When an electron from the n-type side fills a hole on the p-type side, it fills the valence shell. For reference, consider this video: https://youtu.be/7ukDKVHnac4?t=230. I learned in chemistry that ...
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How does this negative voltage generator work?

I managed to fry a piece of moderately rare equipment due to connecting it to the wrong voltage power supply, and I'm now trying to diagnose what's wrong. Luckily, reverse engineered schematics are ...
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Passivity of impedance matrix on the imarinary axis

According to this paper, Section V-C, a rational impedance matrix Z(s) is the impedance of a passive lumped system if and only if the following four conditions are satisfied: 1) each element of Z(s) ...
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Why the opposite of the passive sign convention is not the active sign convention?

Studying the fundamentals of circuit theory, I was reading the Wikipedia article on the Passive Sign Convention and found out about the Active Sign Convention (ASC). After searching many introductory ...
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Finding equivalent capacitance and resistance from DC circuit with combinations of R and C

In order to get the simplest RC circuit and get equivalent circuit tau: How can be its transient studied if before t = 0 there only exists one resistive part of circuit? I's obvious that before t = ...
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CAN Transceiver Behavior during fault conditions

I was just trying to understand the CAN transceiver TJA1042T behavior during fault conditions: CANH short to BATT CANH short to GND CANL short to BATT CANL short to GND I'm powering on the ...
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I'm interested in using the Epson FA04010 printhead in a project. I'm pretty sure it uses piezo-based inkjet tech, and I can see in the product images it has 21 pins. I can't find any specs at all for ...
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Switched circuit analysis - getting rid of “glue” equations

I have the following circuit: simulate this circuit – Schematic created using CircuitLab I would like to derive 3 differential equations, describing it, since it has 3 dynamic components [Csh, ...
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How to go about finding the transfer function of a non-linear circuit?

Note: The concept of Transfer Function is only defined for linear time invariant systems. Nonlinear system models rather stick to time domain descriptions as nonlinear differential equations rather ...
116 views

Second Order Circuit, Sadiku's Fundamentals of Electric Circuits

I would like some help with Sadiku's exercise about second order circuits. I did'nt understand why the solution says that V (0) = -30 V. Also, I did not understand why the capacitor's voltage (Vc) ...
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Series BJT transistors with bases connected through a resistor

For an assignment I was given a problem which consists of two BJT transistors, a PNP and an NPN, in series with their bases tied together. simulate this circuit – Schematic created using ...
143 views

Finding Current in Parallel RLC Circuit with 2 voltage sources?

I've spent sometime learning about step responses for series/parallel RLC circuits, but this problem takes things a step further, since C seems to be in parallel with a series combination of RL and a ...
63 views

Determining the output resistance of a BJT amplifier

I'm given the following amplifier: (all the transistors have the same characteristics; Early effect is neglected) In order to calculate $R_{out}$, we replace the circuit with its small-signal ...
198 views

RL Circuit Analysis with 2 sources, how to find current of resistor?

I've been tackling some problems related to natural and step responses for RL & RC circuits, but I think I've hit a major roadblock for this RL circuit. I'm trying to find the time constant and ...
75 views

Parallel MOSFET Circuit Analysis

I'm solving part b of this question I started with the assumption that both MOSFETs were in saturation mode to simplify calculations, I then solved for the circuit, tested the assumption using vds, ...
115 views

Resistor for buzzer current consumption limiting calculation

I would like to know how did the circuit designer of the circuit in the image calculated resistor R100 value. My guess is that the 100ohm resistor is to limit the current to ~20mA. I have tried to ...
114 views

Howcome there is current flowing through the gate of this transistor?

I have a few conceptual questions: If there wasn't Rg (Resistor between gate and drain), would Vin = Vout then? For small signal analysis, current can flow through the gate (AC) if there's a voltage ...
156 views

How would you find the power balance in this circuit?

I have been having some problems trying to solve the mesh analysis of this circuit to calculate the power balance throughout the circuit. Here is the circuit: simulate this circuit – Schematic ...
355 views

Power stage for VCR (Voltage Controlled Resistor)

I'm building a VCR (Voltage Controlled Resistor) using the LM13700 component. You can read more details on that here: Floating voltage-controlled resistor with LM13700: How does it work? The problem ...
65 views

Voltage drops after connecting two batteries in parallel

I have two batteries 12V GEL 130Ah, each charged to 14.4V. After connecting them together in parallel, the voltage drops gradually and equalizes at 12.99V. (I use 10mm^2 short cables to connect them ...
62 views

Different results for different parallel ports, same circuit. why?

This is my programmer circuit: I decided to try the HCT version of the nor gate (74HCT02) and I also decided to omit the capacitor to the reset. I selected 10K for all resistors except for reset, I ...
99 views

Question on inductors with initial current

Question: Initially the switch position is aa', 3 H is connected across a 3 A supply and 6 H is connected across 6 A supply. After some time the make before break switch is actuated to the new ...
36 views

finding two drain currents

below I have the following problem along with the circuit's picture My analysis is as follows: for G and D open \begin{equation} I_{D1}=I_{D2}\hspace{10mm}therefore\hspace{10mm}V_{ov1}=\:V_{ov2} \...